Diet enriched with the Amazon fruit açaí (Euterpe oleracea) prevents electrophysiological deficits and oxidative stress induced by methyl-mercury in the rat retina

• Published in: Nutritional neuroscience 2017-05, Vol.20 (5), p.265-272
• Main Authors: Brasil, Alódia, Rocha, Fernando Allan de Farias, Gomes, Bruno Duarte, Oliveira, Karen Renata M., de Carvalho, Tayana Silva, Batista, Evander de Jesus O., Borges, Rosivaldo dos Santos, Kremers, Jan, Herculano, Anderson Manoel
• Format: Article
• Language: English
• Subjects: Animals; Diet; Electrophysiological Phenomena; Electroretinogram; Electroretinography; Euterpe; Euterpe oleracea; Fruit; Lipid Peroxidation; Male; Methyl-mercury; Methylmercury Compounds - toxicity; Oxidative stress; Oxidative Stress - drug effects; Rats; Rats, Wistar; Retina; Retina - drug effects; Retina - physiopathology; Retinal Diseases - chemically induced; Retinal Diseases - physiopathology; Retinal Diseases - prevention & control
• ISSN: 1028-415X; 1476-8305
• DOI: 10.1080/1028415X.2015.1119378

Background: The protective effect of a diet supplemented by the Amazonian fruit Euterpe oleracea (EO) against methylmercury (MeHg) toxicity in rat retina was studied using electroretinography (ERG) and biochemical evaluation of oxidative stress. Method: Wistar rats were submitted to conventional diet or EO-enriched diet for 28 days. After that, each group received saline solution or 5 mg/kg/day of MeHg for 7 days. Full-field single flash, flash and flicker ERGs were evaluated in the following groups: control, EO, MeHg, and EO+MeHg. The amplitudes of the a-wave, b-wave, photopic negative response from rod and/or cone were measured by ERGs as well as the amplitudes and phases of the fundamental component of the sine-wave flicker ERG. Lipid peroxidation was determined by thiobarbituric acid reactive species. Results: All ERG components had decreased amplitudes in the MeHg group when compared with controls. EO-enriched food had no effect on the non-intoxicated animals. The intoxicated animals and those that received the supplemented diet presented significant amplitude reductions of the cone b-wave and of the fundamental flicker component when compared with non-intoxicated control. The protective effect of the diet on scotopic conditions was only observed for bright flashes eliciting a mixed rod and cone response. There was a significant increase of lipid peroxidation in the retina from animals exposed to MeHg and EO-supplemented diet was able to prevent MeHg-induced oxidative stress in retinal tissue. Conclusion: These findings open up perspectives for the use of diets supplemented with EO as a protective strategy against visual damage induced by MeHg.